Limiting space used by portage

[atrus]

Recently I've been trying to clean out my hard drive some and after deleting various junk I turned my eye to portage. distfiles was eating about 1GB of space and /var/tmp another 1.6GBs, bringing portage's junk that I don't care about up to 2.5GB which is 31% of my 8GB of space. So after reading the user docs for portage I decided to move distfiles, packages, and temp to /tmp so they'll be completely wiped on boot. I know this will cause me to download things repeatedly every now and then but usually I compile only for upgrades so I have to grab the new source anyway.

I think it would be nice to have some options for tidying up portage, like deleting older sources, possibly placing quotas on the directories it uses with options to be hard or soft (if they're hard then portage would give an error about there being insuffecient space for installation), things like that. Also I don't see the point of letting /var/tmp fill it up if you're not using ccache or something, but resume is nice so perhaps portage should delete the temp compilation directory after the merge is complete.